package string;

public class StringBuilderDemo {
    public static void main(String[] args) {

       /* StringBuilder builder1 = new StringBuilder();//空字符串
        StringBuilder builder2 = new StringBuilder("abc");//abc串

        //String和StringBuilder互转
        String str = "abc";
        StringBuilder builder3 = new StringBuilder(str);
        String str2 = builder3.toString();*/


        String str = "好好学习java";
//        复制str的内容到builder中---好好学习Java
        StringBuilder builder = new StringBuilder(str);

//        append():追加内容---在末尾追加
        builder.append(",为了找个好工作");
        System.out.println(builder);

//        replace():替换部分内容(含头不含尾)
        builder.replace(9,16,"就是为了改变世界");
        System.out.println(builder);

//      delete():删除部分内容(含头不含尾)
        builder.delete(0,8);
        System.out.println(builder);

//      insert():插入内容
        builder.insert(0,"活着");
        System.out.println(builder);

    }
}
